64层螺旋CT与1．5 TMRI在慢性阻塞性肺病患者右心功能测定中的临床应用

Assessment of the right ventricular function in patients with chronic obstructive pulmonary disease and cor pulmonale using cardiac 64-slice spiral CT comparing with 1. 5 T MRI

目的应用64层MSCT评价慢性阻塞性肺病（COPD）患者的右心功能并与MRI结果对照。方法对46例肺功能试验（PFT）证明的COPD患者右心功能进行研究，应用COPD世界分类标准，根据疾病严重程度将COPD患者分为3组，16例轻度，16例中度，14例重度；并将20名年龄与患者组匹配的健康志愿者设为对照组。以上4组均行64层MSCT及MR右心功能检查。应用Pearson相关性分析评价COPD患者右心室射血分数（RVEF）及心肌质量（MM）与MRI结果的相关性。将46例COPD患者MSCT及MR两种方法测量的2组右心功能参数结果：包括舒张末期容积（EDV）、收缩末期容积（ESV）、心搏出量（SV）、射血分数（EF）、MM，进行Pearson相关性分析，采用Bland-Altman法评价两种测量方法的一致性。结果轻、中、重度组和对照组的RVEF分别为（51．6±5．6）％、（49．8±6．0）％、（39．4±7．2）％及（53±5．9）％；MM分别为（44．5±5．4）、（49．6±5．0）、（57．1±3．4）及（40．8±3．9）g，EDV分别为（139．9±25．0）、（130．2±21．2）、（107．6±18．4）及（149．2±27．9）ml，SV分别为（72．1±16．1）、（64．3±11．0），（42．5±16．5）及（77．0±11．7）ml。重度组的RVEF、EDV值比轻、中度组及对照组显著减低（FRVEF=143，FEDV=38．07，P〈0．01），4组的ESV分别为（67．8±16．0）、（66．1±17．4）、（65．1±19．6）、（70．0±20．0）m]，差异均无统计学意义（F=0．669，P=0．518）。轻、中及对照组的RVEF、EDV、ESV、SV值组问两两比较差异均无统计学意义（FKVEF=1．03，FEDr=3．22，FESV=0．44，RSV=2．77，P〉0．05）。但右心室MM在对照组和轻、中、重度组间差异均具有统计学意义（F=66．34，P〈0．01）。MSCT测得的右心功能各参数结果与MRI结果相关性：MM中度相关（r=0．82），右心室容积及RVEF显著相关（右心室舒张末容积、收缩末容积及RVEF的r值分别为0．98、0．97、0．95）。Bland—Altman图显示MSCT与MRI测得的右心功能指标具有高度相关性。COPD患者的RVEF和MM分别与第1秒用力呼气容积有很好的相关性（rRVEF=0．781，FMM=-0．824）。结论重度COPD患者有严重右心功能损伤，与MRI结果比较，MSCT心功能检查可以正确定量评价右心室容积和功能。

Objective To assess the right ventricular function in patients with moderate to severe chronic obstructive pulmonary disease （COPD） and cor pulmonale using cardiac 64 MSCT comparing with MRI. Methods Forty-six patients with COPD determined by pulmonary function test （PFT） were prospectively studied. According to the Global Initiative for COPD classification, the COPD patients were divided into three groups depending on the severity of the disease： mild COPD （ 16 cases）, moderate COPD （16 cases） and severe COPD （14 cases）. Twenty age-matched subjects were included as the controls. The RV function was assessed by 64-MSCT and 1.5 T cardiac MR1 in all four groups. Pearson correlation analysis was used to evaluate the relationship between the right ventricular ejection fraction （RVEF）,myocardial mass （MM） and the PFT results in COPD patients. AP value of less than 0. 05 was considered statistically significant. End-diastolic volume （EDV）, end-systolic volume （ESV）, RVEF and MM on MSCT were compared with that on MRI using Pearson correlation analysis. Bland-Altman plot was used to evaluate the correlation between MSCT and MRI. Results The RVEF was （51.6 ± 5.6） % in mild COPD, （49. 8 ± 6. 0） % in moderate COPD, （39.4 ± 7.2） % in severe COPD, and （ 53 ± 5.9 ） % in controls, respectively. The MM was （44. 5 ± 5.4 ） g in mild COPD, （ 49. 6± 5.0 ） g in moderate COPD, （ 57. 1 ± 3.4） g in severe COPD, and （40. 8± 3.9） g in controls, respectively. The EDV was（ 139. 9 ±25.0）, （130.2221.2）,（107.6±18.4） and （149.2±227.9） ml, the SV was （72. 1 ±16. 1）, （64.3 ±11.0）, （42. 5±16. 5） and （77. 0 ±11.7） ml in four groups, respectively. The values of RVEF and RVEDV were significantly lower in severe COPD than that in mild COPD, moderate COPD and controls （ FRVEF = 143, FRVEDV=38.07,P〈0.01）. TheESVwas （67.8±16.0）,（66.1±17.4）, （65.1±19.6） and （70.0± 20. 0） ml in four groups, respectively. There were not significant differences in ESV between 4 groups （F= 0. 669, P = 0. 518 ）. There were not significant differences in RVEF,EDV,SV,ESV between mild, moderate COPD and controls（FRVEF = 1.03, FEDV = 3.22, FESV =0. 44, FSV = 2. 77, P 〉 0. 05 ）. The MM of the RV was significantly different between controls and the other three groups （ F = 66. 34, P 〈 0. 01 ） . All parameters of the RV function on cardiac CT were correlated well with that on cardiac MRI. The MM of the RV showed moderate correlation （ r = 0. 82 ） , RV volumes and RVEF significant correlation （ r = 0. 98 and 0. 97 for RV EDV and RV ESV, r =0. 95 for RVEF, respectively）. A strong correlation between MSCT and MRI for the assessment of RV function was also found using Bland-Altman plot. The correlation was excellent between the MSCT results and forced expiratory volume in 1 sec （r =0. 781 for RVEF, r= -0. 824 for RV MM） in COPD patients. Conclusions Cardiac MSCT can accurately assess the RV size and function in comparison to MRI. Patients with severe COPD have RV dysfunction.